Influence of the Ambient Pressure on the Weld Quality for Magnetic Pulse Welded Sheet Joints

This paper examines the effect of reduced ambient pressure during the welding process on the quality of magnetic pulse weld seams. For this purpose, a specifically developed vacuum chamber was applied, which enables a reproducible implementation. This, in turn, prepared the ground for a systematic examination of this promising process parameter. The tests focused on comparison of the weld seams realized with different currents and acceleration distances under atmospheric pressure and in the vacuum chamber. Here, both similar (EN AW-1050-H14) and dissimilar material combinations were considered (EN AW-1050A-H14 + S235JR; EN-AW 6016-T6 + DC04). The evaluation criteria for the quality of the welds were the tensile strength of the joint and the size of the weld seam

Analysis of the Weld Seam Area of Magnetic Pulse Welded Aluminium-Steel-Sheet-Connections on its Suitability as a Sign of Quality

This paper deals with the characterisation of the weld seam area of magnetic pulse welded aluminium-steel-sheet-connections for different material combinations and its suitability as a sign of quality. The goal of this work is to suggest a relationship between the weld seam area and the strength of the generated joint. Based on the results of this work, the weld seam area could be established as a basis of design and for dimensioning the magnetic pulse welded hybrid joints. To identify the correlation of the generated weld seam area with the maximum tensile force of the welded samples, several aluminium-steel-joints were welded and tested using tensile shear test. Thereafter, the weld seam area was measured and correlated to the maximum bearable tensile force of the joint. The tested material combinations were EN AW-1050A-H14 / S235JR and EN AW-6016-T6 / HCT780X. The results illustrate a positive linear correlation between the weld seam area of the joint and the maximum tensile force. At the same time further weld seam irregularities were identified which have to be considered for evaluating the suitability of the weld seam area as a sign of quality. Additionally, in order to prevent such irregularities or to ensure a good weld seam, the non-destructive testing method of active thermography is presented

The Neural Cell Adhesion Molecule (NCAM) Promotes Clustering and Activation of EphA3 Receptors in GABAergic Interneurons to Induce Ras Homolog Gene Family, Member A (RhoA)/Rho-associated protein kinase (ROCK)-mediated Growth Cone Collapse

Establishment of a proper balance of excitatory and inhibitory connectivity is achieved during development of cortical networks and adjusted through synaptic plasticity. The neural cell adhesion molecule (NCAM) and the receptor tyrosine kinase EphA3 regulate the perisomatic synapse density of inhibitory GABAergic interneurons in the mouse frontal cortex through ephrin-A5-induced growth cone collapse. In this study, it was demonstrated that binding of NCAM and EphA3 occurred between the NCAM Ig2 domain and EphA3 cysteine-rich domain (CRD). The binding interface was further refined through molecular modeling and mutagenesis and shown to be comprised of complementary charged residues in the NCAM Ig2 domain (Arg-156 and Lys-162) and the EphA3 CRD (Glu-248 and Glu-264). Ephrin-A5 induced co-clustering of surface-bound NCAM and EphA3 in GABAergic cortical interneurons in culture. Receptor clustering was impaired by a charge reversal mutation that disrupted NCAM/EphA3 association, emphasizing the importance of the NCAM/EphA3 binding interface for cluster formation. NCAM enhanced ephrin-A5-induced EphA3 autophosphorylation and activation of RhoA GTPase, indicating a role for NCAM in activating EphA3 signaling through clustering. NCAM-mediated clustering of EphA3 was essential for ephrin-A5-induced growth cone collapse in cortical GABAergic interneurons, and RhoA and a principal effector, Rho-associated protein kinase, mediated the collapse response. This study delineates a mechanism in which NCAM promotes ephrin-A5-dependent clustering of EphA3 through interaction of the NCAM Ig2 domain and the EphA3 CRD, stimulating EphA3 autophosphorylation and RhoA signaling necessary for growth cone repulsion in GABAergic interneurons in vitro, which may extend to remodeling of axonal terminals of interneurons in vivo

Off-label use in germany - a current appraisal of gynaecologic university departments

<p>Abstract</p> <p>Objective</p> <p>The off-label use, referring to the applicability of pharmaceutical drugs beyond the submitted and from the Federal Institute for Drugs and Medical Devices (BfArM, Bundesamt für Arzneimittel und Medizinprodukte) certified and approved administration, is the subject of controversial discussions. the application can be considered in case of severe illness - if no therapeutic alternatives are available - or it exists as a founded perspective for achieving therapeutic success.</p> <p>Methods</p> <p>A latitudinal study for evaluating the application of off-label use supplements was performed at 43 German university and academic teaching hospitals. Five doctors at each hospital applied off-label pharmaceutical drugs and were called upon to share their personal experience to the application of those medications.</p> <p>Results</p> <p>75 (35%) questionnaires were returned out of 22 (51%) medical centres with 215 contacted physicians. Off-label use was common for 65 (91%) of the physicians. Only 9% of them obviate the application of off-label drugs. About a half of the medication is related to application in obstetrics (54%) and in most cases on an every day basis. Uterotonics were the most commonly used off-label medications (34%). The main part of information about off-label use is obtained from personal information of colleagues (66%) and personal experience (58%). 34% of physicians think that off label use is risky. Interestingly, the view about off label use of medication varies considerably among physicians from various hospitals.</p> <p>Conclusions</p> <p>The application of off-label pharmaceutical drugs in Germany seems to be a well established practice. More than 90% of participators of our trial use at least one medication outside the administration. This includes particularly prostaglandins, anti-hyper-tonic therapeutics and chemotherapeutics.</p

Irreducible representations of Upq[gl(2/2)]

The two-parametric quantum superalgebra $U_{pq}[gl(2/2)]$ and its representations are considered. All finite-dimensional irreducible representations of this quantum superalgebra can be constructed and classified into typical and nontypical ones according to a proposition proved in the present paper. This proposition is a nontrivial deformation from the one for the classical superalgebra gl(2/2), unlike the case of one-parametric deformations.Comment: Latex, 8 pages. A reference added in v.

Quantum Dots for Multiplexed Detection and Characterisation of Prostate Cancer Cells Using a Scanning Near-Field Optical Microscope

In this study scanning near-field optical microscopy (SNOM) has been utilised in conjunction with quantum dot labelling to interrogate the biomolecular composition of cell membranes. The technique overcomes the limits of optical diffraction found in standard fluorescence microscopy and also yields vital topographic information. The technique has been applied to investigate cell-cell adhesion in human epithelial cells. This has been realised through immunofluorescence labelling of the cell-cell adhesion protein E-cadherin. Moreover, a dual labelling protocol has been optimised to facilitate a comparative study of the adhesion mechanisms and the effect of aberrant adhesion protein expression in both healthy and cancerous epithelial cells. This study reports clear differences in the morphology and phenotype of healthy and cancerous cells. In healthy prostate epithelial cells (PNT2), E-cadherin was predominantly located around the cell periphery and within filopodial extensions. The presence of E-cadherin appeared to be enhanced when cell-cell contact was established. In contrast, examination of metastatic prostate adenocarcinoma cells (PC-3) revealed no E-cadherin labelling around the periphery of the cells. This lack of functional E-cadherin in PC-3 cells coincided with a markedly different morphology and PC-3 cells were not found to form close cell-cell associations with their neighbours. We have demonstrated that with a fully optimised sample preparation methodology, multiplexed quantum dot labelling in conjunction with SNOM imaging can be successfully applied to interrogate biomolecular localisation within delicate cellular membranes